Added next and prev links to the week view

v1.py

@@ -1,10 +1,12 @@
 from __future__ import absolute_import
 
-from .auth import requires_auth
 from flask import jsonify
 from flask import url_for
 from flask import g
 
+from .auth import requires_auth
+from .weeks import get_next_week, get_prev_week
+
 
 @requires_auth
 def index():
@@ -40,12 +42,11 @@ def serialize_activities(activities):
         if activity.duration <= 0:
             continue
 
-        date = activity.day.strftime("%Y-%m-%d")
         result.append({
                 'id': activity.project_id,
                 'comment': activity.comment,
                 'duration': str(activity.duration),
-                'day': date
+                'day': activity.day.strftime("%Y-%m-%d")
         })
     return result
 
@@ -59,12 +60,29 @@ def get_projects():
     })
 
 
+def get_next_week_url(year, week):
+    y, w = get_next_week(year, week)
+    return url_for(".week", year=y, week=w)
+
+
+def get_prev_week_url(year, week):
+    y, w = get_prev_week(year, week)
+    return url_for(".week", year=y, week=w)
+
+
 @requires_auth
 def get_week(year, week):
     activities = serialize_activities(g.ct.get_week(year, week))
 
     return jsonify({
-            "activities": activities
+            "activities": activities,
+            "links": [{
+                    "rel": "next-week",
+                    "href": get_next_week_url(year, week)
+            }, {
+                    "rel": "prev-week",
+                    "href": get_prev_week_url(year, week)
+            }]
     })
 
 

weeks.py

@@ -0,0 +1,57 @@
+from __future__ import absolute_import
+from datetime import timedelta, datetime, date
+
+import unittest
+
+
+def tofirstdayinisoweek(year, week):
+    """Code taken from http://stackoverflow.com/questions/5882405
+
+    %W takes the first Monday to be in week 1 but ISO defines week
+    1 to contain 4 January. So the result from
+    datetime.strptime('2011221', '%Y%W%w') is off by one iff the first
+    Monday and 4 January are in different weeks. The latter is the
+    case if 4 January is a Friday, Saturday or Sunday. So the
+    following should work"""
+
+    ret = datetime.strptime('%04d-%02d-1' % (year, week), '%Y-%W-%w')
+    if date(year, 1, 4).isoweekday() > 4:
+        ret -= timedelta(days=7)
+    return ret
+
+
+def get_next_week(year, week):
+    current = tofirstdayinisoweek(year, week)
+    d = current + timedelta(days=7)
+    return d.isocalendar()[:2]
+
+
+def get_prev_week(year, week):
+    current = tofirstdayinisoweek(year, week)
+    d = current - timedelta(days=7)
+    return d.isocalendar()[:2]
+
+
+class WeekTestCase(unittest.TestCase):
+    def test_that_tofirstdayinisoweek_finds_monday_31_dec_2012(self):
+        d = tofirstdayinisoweek(2013, 1).date()
+        self.assertEquals(date(2012, 12, 31), d)
+
+    def test_that_tofirstdayinisoweek_finds_monday_2_jan_2012(self):
+        d = tofirstdayinisoweek(2012, 1).date()
+        self.assertEquals(date(2012, 1, 2), d)
+
+    def test_that_next_week_increases_week(self):
+        self.assertEquals((2011, 10), get_next_week(2011, 9))
+
+    def test_that_prev_week_decreases_week(self):
+        self.assertEquals((2011, 8), get_prev_week(2011, 9))
+
+    def test_that_next_week_wraps_year(self):
+        self.assertEquals((2012, 1), get_next_week(2011, 52))
+
+    def test_that_prev_week_wraps_year(self):
+        self.assertEquals((2011, 52), get_prev_week(2012, 1))
+
+if __name__ == "__main__":
+    unittest.main()